Modern digital cameras utilize a feature known as “autofocusing” which is used to determine an accurate focus position prior to capturing an image. Determining an accurate focus position is essential to capturing the sharpest image possible. Autofocus systems generally employ an array of external focus sensors used for determining an accurate focus position as well as a motor to facilitate lens movement so that the lens is in position to capture an image at the determined focus level. These external focus sensors measure focus position through the use of beam splitting techniques in which one beam is directed into an image sensor used to capture the final image and the other beam is directed into the view finder of the camera.
However, many digital cameras, including those used in mobile devices, are not equipped with these external focus sensors and, thus, rely on the image sensor to perform autofocus functionality as well. Current autofocusing technology is inefficient in the sense that it takes longer than necessary to locate an optimum fixed lens position and often uses redundant lens positions in determining this optimum focus position. These inefficiencies are costly not only in terms wasted computation time, but also result in wasted power resources. Furthermore, these inefficiencies may lead to user frustration at not being able to instantaneously capture images of the sharpest quality.